Embodiments disclosed herein generally relate to pivoting tube brushes, such as may be utilized in tube cleaning operations. In some embodiments, a pivoting tube brush may be utilized in fire-tube boilers and provide solutions to the problem of cleaning the interior surface of fire-tubes with a lighter weight, easier to use machine.
The general construction of a fire-tube boiler is a tank of water penetrated by tubes that carry the hot flue gases from the boiler's combustion chamber. The tank is usually cylindrical for the most part (being the strongest practical shape for a pressurized container) and this cylindrical tank may be either horizontal or vertical. In a fire-tube boiler a large number of fire-tubes are arranged in a boiler drum for generating a large amount of steam (hot water) for its size as compared to flue boilers. Hot combustion gases pass through fire-tubes running through the sealed boiler drum containing water. The heat of the gases is transferred to the water through the walls of the tubes ultimately creating steam. The many small tubes offer far greater heating surface area for the same overall boiler volume. In operation, surface area heat transfer efficiency is diminished by buildup on the fire-tube interior surfaces by products of corrosion, oxidation, soot, and chemical reactions. Fire-tube boiler cleaning machines are available for tube cleaning, however, such machines are very heavy and hard to use in tight spaces or on elevated catwalks, platforms, or scaffolding. Machine weight is determined by the physics of pushing a rigid cleaning brush in a forward stroke down the full length of a tube by means of a steel tape. The steel tape needs to be thick and heavyweight to resist the significant compressive forces encountered in pushing the brush along the tube. Additionally, the machine needs sufficient mass (weight) to withstand the high loads developed on the brush forward stroke.
Some embodiments disclosed herein deal with the main problem of conventional fire-tube cleaners, i.e., the weight of the cleaner and component parts. Solutions disclosed herein provide a unique and brilliant way of substituting fire-tube boiler mass for the mass needed by conventional machines to withstand the high loads developed on the brush forward stroke. Embodiments disclosed herein generally, for example, take advantage of boiler mass by providing a machine for tube cleaning on reverse stroke.